| Line | Label | Object Class | Period Type | Balance | Name |
| 1 | 101000 - Document - Document Information | [Network] | http://www.abc.com/role/DocumentInformation | ||
| 2 | Document Information [Table] | [Table] | dei:DocumentInformationTable | ||
| 3 | Report Date [Axis] | [Axis] | us-gaap:CreationDateAxis | ||
| 4 | Financial Statements Date [Domain] | [Domain] | us-gaap:DefaultFinancialStatementsDateMember | ||
| 5 | As Reported February 12, 2011 [Member] | [Member] | For Period | abc:AsReportedFebruary122011Member | |
| 6 | Legal Entity [Axis] | [Axis] | dei:LegalEntityAxis | ||
| 7 | Consolidated Entity [Domain] | [Domain] | dei:EntityDomain | ||
| 8 | Class of Stock [Axis] | [Axis] | us-gaap:StatementClassOfStockAxis | ||
| 9 | Class of Stock [Domain] | [Domain] | us-gaap:ClassOfStockDomain | ||
| 10 | Common Class A [Member] | [Member] | us-gaap:CommonClassAMember | ||
| 11 | Common Class B [Member] | [Member] | us-gaap:CommonClassBMember | ||
| 12 | Document Information [Line Items] | [Line Items] | dei:DocumentInformationLineItems | ||
| 13 | Document Information [Hierarchy] | [Abstract] | abc:DocumentInformationHierarchy | ||
| 14 | Entity Registrant Name | [Concept] Text/String | For Period | dei:EntityRegistrantName | |
| 15 | Entity Central Index Key | [Concept] CIK Number | For Period | dei:EntityCentralIndexKey | |
| 16 | Entity Filer Category | [Concept] Filer Category | For Period | dei:EntityFilerCategory | |
| 17 | Entity Current Reporting Status | [Concept] Yes/No | For Period | dei:EntityCurrentReportingStatus | |
| 18 | Entity Voluntary Filers | [Concept] Yes/No | For Period | dei:EntityVoluntaryFilers | |
| 19 | Entity Well-known Seasoned Issuer | [Concept] Yes/No | For Period | dei:EntityWellKnownSeasonedIssuer | |
| 20 | Entity Public Float | [Concept] Monetary | As Of | Credit | dei:EntityPublicFloat |
| 21 | Document Type | [Concept] Submission Type | For Period | dei:DocumentType | |
| 22 | Amendment Flag | [Concept] Yes/No | For Period | dei:AmendmentFlag | |
| 23 | Document Fiscal Period Focus | [Concept] Fiscal Period | For Period | dei:DocumentFiscalPeriodFocus | |
| 24 | Document Fiscal Year Focus | [Concept] Year | For Period | dei:DocumentFiscalYearFocus | |
| 25 | Document Period End Date | [Concept] Date | For Period | dei:DocumentPeriodEndDate | |
| 26 | Current Fiscal Year End Date | [Concept] Month/Day | For Period | dei:CurrentFiscalYearEndDate | |
| 27 | Entity Common Stock, Shares Outstanding | [Concept] Shares | As Of | dei:EntityCommonStockSharesOutstanding | |
| 28 | Trading Symbol | [Concept] Text/String | For Period | dei:TradingSymbol |